Transportation within Rapture is provided by Rapture Metro, a connected bathysphere system, which consists of spherical pressurized capsules, through which citizens could access most areas of the city. Part of Rapture Metro is the bathysphere inside the remote lighthouse in the North Atlantic, which is Rapture's only entrance from the outside world. Another mode of transportation within Rapture is the Atlantic Express, a pressurized rail system for moving a larger number of citizens (though this mode of transportation was decommissioned a long time ago). Other areas of Rapture are connected through bulkhead doors. Areas within some levels are connected by glass tunnels: smaller ones for pedestrians, larger ones for tramways of a rail system between areas. Rapture is intentionally isolated from the world and the only way to access it seems to be bathyspheres taken down from the lighthouse perched on an island above.
One of the major breakthroughs achieved in Rapture was the discovery of ADAM: unstable stem cells from a species of sea slug. This led to the creation of both Plasmids and Gene Tonics. Essentially, ADAM allowed a user to splice new genetic material into the user's DNA, enhancing health, intellect and even giving superpowers. However, ADAM was soon found to cause physical and mental damage as more of the user's native cells were replaced by unstable stem cells. The need for ADAM became an addiction, which became more pronounced by excessive splicing, mainly during and after Rapture's civil war.
The scientists of Rapture were also notable for discovering Seabed's Nectar, and two species associated with it: the Clover creatures and their Human Scale Parasites. Much research regarding Seabed's Nectar took place in Rapture, often along side research into ADAM. The two were often used in combination during experiments, producing dangerously unpredictable results. Scientists also attempted to control Clovers and their Parasites, hoping to use them as weapons of war. Thankfully, these experiments were ended with the fall of Rapture.
On December 31, 1974, a massive working-class uprising, led by Atlas, occurred in upper-class locations. This sparked a civil war between Atlas and Rapture's founder, Andrew Ryan. This was mainly due to the addictive need for ADAM in most of the city's residents. During the 1974 New Year's Eve Riots, traditional ballistic weapons and Plasmids were used on both sides. The major conflict lasted about four months, but the violence continued to break apart the society of Rapture. In the end, almost all of the sane population of the city was either killed off by Splicers or committed suicide and ordered society in Rapture came to an end.